Electron-discharge device



Aug. 14, 1928.

H. J. NOLTE ELECTRON DISCHARGE DEVICE Original Filed Feb. '7. 1921 /&

lnx/e ntorz Henry J Nome,

His Attorney.

Patented Aug. 14, 1928. I

UNITED STATES 80,6 PATENT OFFICE.

HENRY J. NOLTE, OF SCHENECTADY, NEW YORK, ASSIGNOB '10 GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

ELECTRON-DISCHARGE DEVICE.

Original application filed February 7, 1921, Serial No. 443,005. Dividedand this application filed September 18, 1923.

My presentinvention, which is a division of my rior application, SerialNo. 443,005, filed ebruary, 7, 1921, relates to electron dischargedevices, and more particularly to devices of the type employing at leastthree electrodes, comprising a cathode, an anode and a grid member forcontrolling-the passage of an electron stream between cathode and anode.

The object of my invention is to provide an eflicient and convenientmethod for removing occluded gas from the electrodes of such devicesduring the process of exhaust. The novel features which I believe to becharacteristic of my invention are set forth with particularity in theappended claims; the invention itself, however, will best be understoodb reference to the following description talzen in connection with theaccompanying drawing in which Fig. 1 is a view partly in section of adevice with which my invention may conveniently be employed; Fig. 2 is aview of the grid and the structure whereby it is supported; and Figs. 3and 4 are detail views of portions of the grid structure.

The device indicated in the drawingcomprises an evacuated receptaclecomprising a portion 1 of glas and a portion 2 of metal. The lassportion is sealed to the metal ortion y means of a thin metal ring 3 w'ch is preferably of copper or an alloy having substantially the samecoefiicient of. expansion as the glass of which the art 1 is composed.This rin 3 is solder or 'welded to the portion 2 and forms a gas-tightseal with the glass at the-region 4 where it is surrounded by the glasswall of the portion 1. The filamentary cathode 5, which is prefer- Iably of tungsten is supported within the receptacle by means ofsupporting arms 6, 7 and 8, the arms 6 and 7 also serving as supplyconductors of the cathode. The grid 15, which surroundsthe cathode is inthe N. form of a cylindrical screen made up "of two sets of wires 16,17, which are wound spirally in opposite directions and interwoven. Bymeans of this construction the principal'expansion ofthe grid whenheated will occur in the direction of its diameter and the tendency ofthe grid to buckle and make contact with the filament or anode will belargely eliminated. The ends of these two se s of grid are se ured 2Serial No. 663,470.

rings 18., and 19 by means of binding wires wound around these rings.Supporting arms 20 are secured to these two rings and together with therings form a rigid support for the grid. These supporting arms and theend rings preferably are made of tungsten or similar metal from whichthe oc-.

its edges. This strip of metal is bent into the form of a ring, theseears bent over and the arms 20 inserted through the holes 23 in the cars22. The arm 20, which passes through the holes 23 at the ends of thestrip which comes opposite each other also serves to hold the two endsof the strip together. After the arms 20 are inserted in these holes theears may be squeezed or bent in such a way as to firmly grip the arms 20and'thereby secure the parts together without the necessity of anyweldedor soldered joints.

The grid structure described is supported in I the desired position inthe receptacle by means of a sleeve 24 which surrounds the reentranttubular portion 12 and is securely fastened thereto by means of clampingscrew 25. S'upport' arms 26 are secured to this sleeve 24 and e members20 which are of considerabl smaller-diameter than the diameter of t earms 26 are fastened to the arms 26 in the manner indicated at 27 inFig. 2. For convenience in the construction of the device the end of theportion 2 of the receptacle may be left open until the arts have beensealed together and then 0 osed by means of a cap 28 which is solderedto the receptacle or welded thereto to form an air-tight joint. K

In the operation of the devicedescribed for the control of largeenergies, the anode 2 should be artificially cooled. This may beaccomplished by placing it in a bath of water or other suitable coolingliquid and providing means to insure d circulation of the coolingliquid. In view of the fact,

therefore, that the anode 2 will normally operate at a low temperature,it is possiblg to make use of metal for its construction having a comaratively low melting, point. I have found is at copper is very suitab efor this purpose. I

5 In the exhaustion of the device described,

toremove all air as well as all the gases potential is connected betweencathode and anode so that the anode will be bombarded by electronsemitted'from the cathode. At'

this point in the exhaust the cooling medium 0 is applied to the anodeto protect it from ,over eating and the gas removed during this stage lstherefore removed principally as a result of bombardment Occluded gas isalso removed from the grid structur'e by bombarding the grid and itssupporting parts by electrons given off from the cathode. What I claimas new and desire to secure by Letters Patent of the United States is 1.The method of removing occluded as during the exhaustion of an electronischarge device comprising a filamentary cathode adapted to be heated toincandescones and an anode, which'consists in first heating the anode,by heat radiated from the cathode, to a temperature sufiiciently high todrive ofi a large portion of the occluded gas in the metal parts of thedevice, and then bombarding the anode b means of electrons emitted fromthe catho e.

2. The method of removing occluded gas during the exhaustion of anelectron discharge device comprising a cathode adapted to be heated toincandescence and an anode, which consists in first heating the anode byheat radiated from the cathode, then bombarding the anode by means ofelectrons emitted from the cathode and maintaining the anode at anappreciably lower temperagure during the second step than during the'rst. t

3. The method of removing occluded gas during the exhaustion ofanelectron discharge device comprising a cathode adapted to be heated toincandescence and an anode which consists in first heating the anode byheat radiated from the cathode, then bombarding the anode by means ofelectrons emitted from the cathode and simultaneously supplying acooling medium to the anode.

4. The method of removing occluded as during the exhaustion of anelectron 'scharge device includin a cathode and an anode, whichcomprises eating the anode to a red heat by means of heat radiated fromthe cathode, and then bombarding the anode by means of electrons emittedfrom the cathode.

In witness whereof, I have hereunto set my hand this 17th da ofSeptember, 1923.

NRY J. NOLTE.

